range of energies that electromagnetic radiation can comprise, including radio, microwaves, infrared, visible, ultraviolet, X-rays, and gamma rays; since electromagnetic radiation energy is proportional to the frequency and inversely proportional to the wavelength, the spectrum can also be specified by ranges of frequencies or wavelengths

chemistry is one of the three main branches of pure science the other two being physics and biology. chemistry deals with the composition properties and uses of matter. it probes into the principle governing the changes that matter undergo.